From the past, in the field of robotics, it is preferable to prevent an excessive load from acting on a robot or an object existing around the robot. For this reason, various technologies for detecting generation or non-generation of a contact (external force) to the robot are studied. For example, a technology is known which installs a force detector in a base end of a robot arm to detect the external force, and stops an operation of the robot arm on the basis of the detection result of the force detector or causing the robot arm to move in the direction capable of reducing the effect of the external force when the excessive external force is applied. The relevant technologies of the related art are described, for example, in Japanese Patent Application Laid-Open (JP-A) Nos. 2006-21287 and 2007-203380.
However, in the related art in which the force detector is simply provided in the robot, the response of the force detector to the contact of the robot arm is late, which may become an obstacle in detecting a light or momentary touch with a high degree of precision and improving the functionality of the robot.